This invention relates to the field of heat exchangers, and more particularly to a heat exchanger with metal tubes, a plastic main shell extrusion, and plastic manifolds.
In marine applications, a heat exchanger is used to cool the engine. The space available for installation of a heat exchanger is limited, due to engine compartment configurations. Typically, the space is adequate in length fore-and-aft, and in height, but limited in width transversely. Heat exchangers in the prior art are housed in either a circular cylinder or a flat plate box. A circular cylinder of adequate,capacity will not fit into the limited space. The pressure inside the cooling system is about 15 psi. A flat plate of only 12 by 24 inches will develop 4320 lbs of force under 15 psi. A flat-sided box will not withstand the pressure. Other considerations in a marine system are corrosion due to electrolysis, and fouling by marine organisms such as mussels, barnacles, algae, and weeds.
Plastic heat exchangers are known, and have taken a variety of configurations in the past. Some examples of plastic heat exchangers in the art are found in these patents:
Heier, U.S. Pat. No. 6,929,060; shows metal tubes mounted into a plastic manifold. The enclosure is flat-sided.
Stafford, U.S. Pat. No. 4,323,115; discloses a shell and tube heat exchanger with metal tubes set into plastic sheets. The enclosure is cylindrical.
Baker, U.S. Pat. No. 3,363,680; illustrates a shell and tube heat exchanger with plastic tubes. The enclosure is cylindrical.
Humpolik, U.S. Pat. No. 4,576,223; shows metal tubes mounted into a plastic sheet and plastic manifold. The enclosure is flat-sided.
Accordingly, there is a need to provide a heat exchanger that can provide significant capacity within a limited width space.
There is a further need to provide a heat exchanger of the type described and that can withstand at least fifteen pounds per square inch internal pressure.
There is a yet further need to provide a heat exchanger of the type described and that will resist electrolytic corrosion in a salt-water environment.
There is a still further need to provide a heat exchanger of the type described and that will resist the growth of marine organisms.
There is another need to provide a heat exchanger of the type described and that can be manufactured cost-effectively in large quantities of high quality.